From patchwork Tue Nov 3 20:37:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 320469 Delivered-To: patch@linaro.org Received: by 2002:a92:7b12:0:0:0:0:0 with SMTP id w18csp4917583ilc; Tue, 3 Nov 2020 13:15:42 -0800 (PST) X-Google-Smtp-Source: ABdhPJxaE8/20JFeavn5DQql5CWI/2Ktugvg4vChRqvVwV62oiDh54GMC51YrUeYkVYdUUJQuwer X-Received: by 2002:a17:906:b53:: with SMTP id v19mr21671465ejg.136.1604438142755; Tue, 03 Nov 2020 13:15:42 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1604438142; cv=none; d=google.com; s=arc-20160816; b=St5EkF6n2w5f//RR0Ow4fIYnGV3/YbzM5EKvPMunXaa2GGQ0lxGMA4QWRA/WM54X3x UWjMT1K1WWgjv3aBy9csat2hhh6zDsN6VsyQlbtOvvzQhQSWFxGAdqvvaO+mzWUYHS60 kfx0Ojm6uITbVc3ese1rGBaiPfLnexiM7N07TQlUFX1ShDWAYINhQNHI0xFIpXWtQDwJ MOUdEbkEmXI0UIFEZNwa73Ynt9cHgfLsRAezpSbg6k1DVd00yeG4Qn1ioeDGYzFcinYT PS7L+jbqCD08Brw8e7XPfjH1ZK9zCvCttV7T4yOxasqek8rLBf9h+OKAGOQBrHEmb1x+ FtVw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=qDDh9dxWaRkQCl0oA00hUg244dO/aVqYgOXaZIUA84I=; b=inZo3e2fyBXZSNMUU4rgnr9tfUTWY0ihZNeBkIOBY8B3hfJXDjRmEwSt12z1UHR/WH NFyWCNRVnTS4/p2ee0yTZrILUKFiETQ8sWpTcuTStFwwTSiMcktXhggazRCM3drS09Af /SkYhn3g8Vch+Fuve7n737qld8mM8XpbWrDVjSMy3TR3Xq2rK12n/kxqy7yXHvz1+JPf i74cpxRYK4gZ8n4I1WArLy6O3H7WnEMosfHYD0JTLf5LnJN4eK1EU+nBjZCqygd5t4WB ca6M1REDtDbiHQYfBLTtR/Kb10hS4qu46tG1ULhRTbrjODtp+BLojPFWVSKpys0dfCtj wmlA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=UVeqhPuw; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id y98si9689792ede.197.2020.11.03.13.15.42; Tue, 03 Nov 2020 13:15:42 -0800 (PST) Received-SPF: pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=UVeqhPuw; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388962AbgKCVME (ORCPT + 15 others); Tue, 3 Nov 2020 16:12:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:54160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388942AbgKCVMD (ORCPT ); Tue, 3 Nov 2020 16:12:03 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CF72120757; Tue, 3 Nov 2020 21:12:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437922; bh=Sc22hHC5x/A69Ljw+UA6/Br5HDR8C/JbPvO9urOWKV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UVeqhPuwILU70xUXmmKBl9Ul/AblX8h3HCZw/a+m7emHs68t0/DrEMdxfFhAXZu8o A4jl5TS7dI72czXWzEZRWfgvyf4CffuoIqhpre3QQz6aXY5AMe/DPcvRs/E9bzFCMX hrUhRlDIMF/7IwB5LfWZ1O2jMIGhfc9RZDWtQT3g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Andy Shevchenko , Akinobu Mita , Stable@vger.kernel.org Subject: [PATCH 4.14 089/125] iio:adc:ti-adc12138 Fix alignment issue with timestamp Date: Tue, 3 Nov 2020 21:37:46 +0100 Message-Id: <20201103203209.751660437@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203156.372184213@linuxfoundation.org> References: <20201103203156.372184213@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jonathan Cameron commit 293e809b2e8e608b65a949101aaf7c0bd1224247 upstream. One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses an array of smaller elements on the stack. We move to a suitable structure in the iio_priv() data with alignment explicitly requested. This data is allocated with kzalloc so no data can leak apart from previous readings. Note that previously no leak at all could occur, but previous readings should never be a problem. In this case the timestamp location depends on what other channels are enabled. As such we can't use a structure without misleading by suggesting only one possible timestamp location. Fixes: 50a6edb1b6e0 ("iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Andy Shevchenko Cc: Akinobu Mita Cc: Link: https://lore.kernel.org/r/20200722155103.979802-26-jic23@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/ti-adc12138.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/iio/adc/ti-adc12138.c +++ b/drivers/iio/adc/ti-adc12138.c @@ -50,6 +50,12 @@ struct adc12138 { struct completion complete; /* The number of cclk periods for the S/H's acquisition time */ unsigned int acquisition_time; + /* + * Maximum size needed: 16x 2 bytes ADC data + 8 bytes timestamp. + * Less may be need if not all channels are enabled, as long as + * the 8 byte alignment of the timestamp is maintained. + */ + __be16 data[20] __aligned(8); u8 tx_buf[2] ____cacheline_aligned; u8 rx_buf[2]; @@ -333,7 +339,6 @@ static irqreturn_t adc12138_trigger_hand struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct adc12138 *adc = iio_priv(indio_dev); - __be16 data[20] = { }; /* 16x 2 bytes ADC data + 8 bytes timestamp */ __be16 trash; int ret; int scan_index; @@ -349,7 +354,7 @@ static irqreturn_t adc12138_trigger_hand reinit_completion(&adc->complete); ret = adc12138_start_and_read_conv(adc, scan_chan, - i ? &data[i - 1] : &trash); + i ? &adc->data[i - 1] : &trash); if (ret) { dev_warn(&adc->spi->dev, "failed to start conversion\n"); @@ -366,7 +371,7 @@ static irqreturn_t adc12138_trigger_hand } if (i) { - ret = adc12138_read_conv_data(adc, &data[i - 1]); + ret = adc12138_read_conv_data(adc, &adc->data[i - 1]); if (ret) { dev_warn(&adc->spi->dev, "failed to get conversion data\n"); @@ -374,7 +379,7 @@ static irqreturn_t adc12138_trigger_hand } } - iio_push_to_buffers_with_timestamp(indio_dev, data, + iio_push_to_buffers_with_timestamp(indio_dev, adc->data, iio_get_time_ns(indio_dev)); out: mutex_unlock(&adc->lock);